Developer's Tips and Tricks

Adding instance of WebUserControl to ASP.Net website project

2011-03-21T19:22:00.000+11:00

It can easily be done using namespaces. Here's an example:

WebControl1.ascx:

Notice that Inherits references the namespace (MyUserControls), and not just the class name (WebControl1)

WebControl1.ascx.cs:

namespace MyUserControls { public partial class WebControl1 : System.Web.UI.UserControl { protected void Page_Load(object sender, EventArgs e) { } } } Notice that the class have been included in the namespace MyUserControls

Default.aspx.cs:

using MyUserControls; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { var control = (WebControl1) Page.LoadControl("~/WebControl1.ascx"); } } This approach potentially allow you to redistribute your user controls (or keep them in a separate project) without the hassle of referencing them in your .aspx files.

ASP.Net AJAX CalendarExtender - Get selected date from ReadOnly TextBox

2011-03-01T20:24:00.000+11:00

In this article I will explain a very common issue faced while using the ASP.Net AJAX Control Toolkit CalendarExtender control.
Issue
Whenever for the ASP.Net Textbox if the ReadOnly property of the Textbox is set to true, the selected data is not available in the Text property of the Textbox on PostBack.

Reason

The reason behind this issue is that whenever value of an ASP.Net Textbox is set to ReadOnly and the value of the textbox is set client side using client side script like JavaScript, in such cases the value of the Textbox is not available in the Text property of the ASP.Net Textbox. The ASP.Net AJAX Control Toolkit CalendarExtender makes use of JavaScript to set the selected date in the Textbox.

Solution

The solution to the issue is making use of Request.Form collections. As this collection has values of all fields that are posted back to the server and also it has the values that are set using client side scripts like JavaScript.

Thus we need to do a small change in the way we are fetching the value server side.

C#

protected void Submit(object sender, EventArgs e)
{
string date = Request.Form[txtDate.UniqueID];
}

As you can see above I am fetching the value of the Textbox from the Request.Form collection using the UniqueID property of the Textbox which is nothing but Client Side name of the ASP.Net TextBox control
The screenshot below describes that the selected date value is now available server side when fetched using the Request.Form collection

Read Text value from ReadOnly TextBox

2010-08-20T20:12:00.000+10:00

Some time we need to make textbox read-only for showing data. If we make textbox read-only at the designer setting as below, then the textbox always returns blank in the code behind.

Here I am giving you an example of the issue and the solution.
For date picker I used ASP.NET AJAX 's Calendar extender that can be attached to any ASP.NET TextBox control only. And in the textbox I don't want that user directly write any text.
For achieving this, if I make textbox read-only then at the server side textbox.text will come as blank(empty).
Solution

In code behind add an attribute.

txtDate.Attributes.Add("readonly", "readonly");

By doing this we can retrieve read-only textbox's value in the code behind.

Color coding List item based on date

2010-05-21T17:26:00.001+10:00

We had a need to maintain a set of books as library. I decided to go with SharePoint list with 'Issued Date' as DateTime column and 'Due Date' column as calculated column (Issued Date + 14 days).
The formula for 'Due Date' is =[Issued Date]+14

Added one more column of type 'Yes\No' with name 'Returned' to note if the book has been returned or not.

Ok, now i have to display the row in yellow(or light pink) if today's date is just 3 days or less away from 'Due Date', make it red if today's date is 'Due Date' or crossed. All other rows in green.
To do this on client side, CEWP had to be added to the page as the last WebPart.
The script to check for the date and change the row color was

<script type="text/javascript">
// Change these variables to suit your needs
var green = 3; // Items this many days out will be green
var yellow = 1; // Items that are this many days or more are yellow

var tbls = document.getElementsByTagName("TABLE");
var col = new Array();
for (var t in tbls) {
if (tbls[t].className == "ms-listviewtable") {
var rows = tbls[t].childNodes[0].childNodes;
var hRow = rows[0].getElementsByTagName("TH");
for (i=0;i<hRow.length;i++) {
col[i] = (hRow[i].innerText || hRow[i].textContent) + "";
col[i] = col[i].replace(/n/,"");
}
for (r=1;r<rows.length;r++) {
for (c=0;c<col.length;c++) {
if ((col[c] == 'Due Date') && (rows[r].childNodes[c+1].innerText == 'No')) {
colorIt(rows[r],rows[r].childNodes[c],green,yellow);
}
}
}
}
}

function colorIt(row,x,green,yellow) {
var strDate = x.innerText || x.textContent;
var dt1 = parseInt(strDate.substring(0,2),10);
var mon1 = parseInt(strDate.substring(3,5),10);
var yr1 = parseInt(strDate.substring(6,10),10);
mon1 = mon1 - 1;

var startDate = new Date(yr1, mon1, dt1);
var today = new Date();
var toDate = new Date(today.getFullYear(), today.getMonth() , today.getDate());
var dateDiff = (startDate - toDate )/86400000;;

if (dateDiff > green) {
row.style.backgroundColor='#66FF99';
} else if (dateDiff >= yellow) {
row.style.backgroundColor='Pink';
}
else
{
row.style.backgroundColor='#CC0066';
}
}
</script>

Color Coded SharePoint Calendar

2010-05-21T17:10:00.001+10:00

Once i had to give different color for the Calendar items. Below are the steps i followed

1. Created one Calculated Column with title 'ColorTitle'
2. Added the formula

="<div style='border: 1px solid #009933; padding: 3px; margin: 0px; background-color: #FFFFB0; color: #009933'>"&Title&"</div>"

3. Edited the default view as below
a. Chose 'ColorTitle' for Month View Title
b. Chose 'ColorTitle' for Week View Title

Saved the view. Thats all :)

Note: You can change the color based on a field value by slightly modifiying the formula.

Hide fields of SharePoint Calendar

2010-05-21T17:03:00.000+10:00

I wanted a Calendar in my team site without fields 'Recurrence' and 'Workspace'. Since it was production server, i cannot do any custom coding, installation or configuration and even i cannot use any tool to tweak the fields.
So, the solution is to do with JavaScript + CEWP.
Go to the Display.aspx form and EditForm.aspx through an item in calendar and bring the page into edit more to include the CEWP.

One trick to bring the Displayform or editform to edit mode, just append "toolpaneview=2" after ".aspx" in the address bar of browser
.......DisplayForm.aspx?toolpaneview=2 or
-----EditForm.aspx?toolpaneview=2

Add CEWP to the bottom of page. Add the following script to the CEWP

<script type="text/javascript">
var trs = document.getElementsByTagName("TR");</P><p>
for (var r in trs) {
var row = (trs[r].innerText
trs[r].textContent)+"";
if (row.match(/^Workspace/)) { trs[r].style.display = "none"; }
if (row.match(/^Recurrence/)) { trs[r].style.display = "none";}
}
</script>

Show traffic lights in SP List based on Checkbox(Yes\No) column

2010-04-06T22:20:00.000+10:00

I had to create a SharePoint list with traffic lights as shown below.

The decision for color of traffic light is from a Checkbox field.

One calculated field for each traffic light has to be created with formula like
="< d i v >< i m g src="http://www.blogger.com/_layouts/images/KPIDefault-%22&IF([Gate%201]=TRUE,"0.GIF","2.GIF")&"" /> < / d i v >"

The idea is to use the existing SharePoint KPI images.

Since the formula is based on Checkbox, the following IF condition will work.
="< d i v >< i m g src="http://www.blogger.com/_layouts/images/KPIDefault-%22&IF([Gate%201]=TRUE,"0.GIF","2.GIF")&"" /> < / d i v >"
"

Did NOT work:
="< d i v >< i m g src="http://www.blogger.com/_layouts/images/KPIDefault-%22&IF([Gate%201]=Yes,"0.GIF","2.GIF")&"" /> < / d i v >"

="< d i v >< i m g src="http://www.blogger.com/_layouts/images/KPIDefault-%22&IF([Gate%201]=1,"0.GIF","2.GIF")&"" /> < / d i v >"

It will just set the HTML tags to the calculated field based on the checkbox value.
How to make the browser to interpret the HTML tags and display the image.

Here comes the handy script from http://blog.pathtosharepoint.com/2008/09/01/apply-color-coding-to-your-sharepoint-lists/

A CEWP has to be added at bottom of the page and include the following script in the CEWP, thats all.
It does magic for you...

< s c r i p t type="text/javascript">
//
// Text to HTML
// Feedback and questions: Christophe@PathToSharePoint.com
//
var theTDs = document.getElementsByTagName("TD");
var i=0;
var TDContent = " ";
while (i < theTDs.length) { try { TDContent = theTDs[i].innerText || theTDs[i].textContent; if ((TDContent.indexOf("") >= 0)) {
theTDs[i].innerHTML = TDContent;
}
}
catch(err){}
i=i+1;
}
//
// ExpGroupRenderData overwrites the default SharePoint function
// This part is needed for collapsed groupings
//
function ExpGroupRenderData(htmlToRender, groupName, isLoaded) {
var tbody=document.getElementById("tbod"+groupName+"_");
var wrapDiv=document.createElement("DIV");
wrapDiv.innerHTML="
<><><><>"+htmlToRender+"

";
var theTBODYTDs = wrapDiv.getElementsByTagName("TD"); var j=0; var TDContent = " ";
while (j < theTBODYTDs.length) { try { TDContent = theTBODYTDs[j].innerText || theTBODYTDs[j].textContent; if ((TDContent.indexOf("") >= 0)) {
theTBODYTDs[j].innerHTML = TDContent;
}
}
catch(err){}
j=j+1;
}
tbody.parentNode.replaceChild(wrapDiv.firstChild.firstChild,tbody);
}
< / s c r i p t >

ReportViewer in WebPart (SharePoint)

2010-01-04T23:39:00.004+11:00

Using ReportViewer control inside SharePoint Webpart is bit tricky and challenging.
Below are the steps to make it happen.

1. web.config (of SharePoint) changes (Extra space has been included after > and < to make it appear in blog)

add below line to < httpHandlers > section

< add verb="*" path="Reserved.ReportViewerWebControl.axd" type = "Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" / >

and below line to < assemblies >

< add assembly="Microsoft.ReportViewer.WebForms, Version=9.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" / >

2. Add Report (.rdlc) and DataSet (.xsd) files to Solution

Sample Code

------------------------------------------------------------
using System;
using System.Text;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using Microsoft.Reporting.WebForms;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;

namespace ReportWebpart
{
public class ReportsWP : WebPart
{
Label lblTime;
ReportViewer ReportViewer1;
TextBox tb1;
Button btn;

protected override void CreateChildControls()
{
base.CreateChildControls();
try
{
lblTime = new Label();
lblTime.Text = "Enter Plant No.";

tb1 = new TextBox();

btn = new Button();
btn.Text = "Refresh Report";
btn.Click += new EventHandler(btn_Click);

ReportViewer1 = new ReportViewer();
ReportViewer1.Width = Unit.Percentage(80);
ReportViewer1.EnableViewState = true;
ReportViewer1.LocalReport.ReportPath = @".\Report1.rdlc"; // Copy the rdlc file to root of IIS
ReportViewer1.ProcessingMode = ProcessingMode.Local;
ReportViewer1.ID = "rprtViewer1";

this.Controls.Add(lblTime);
this.Controls.Add(tb1);
this.Controls.Add(btn);
this.Controls.Add(ReportViewer1);
}
catch (Exception ex)
{
string k = ex.Message;
}
}

void btn_Click(object sender, EventArgs e)
{
DataTable newDT = GetTable();
ReportViewer1.LocalReport.DataSources.Clear();
ReportViewer1.LocalReport.DataSources.Add(new ReportDataSource("DataSet1_Employee", newDT));//Name of Dataset (.xsd file)+ '_' + table name
ReportViewer1.ID = "rprtViewer1";
ReportViewer1.DocumentMapCollapsed = true;
ReportViewer1.LocalReport.Refresh();
}

private DataTable GetTable()
{
//FRAME THE QUERY AS NEEDED. THE FIELDS RETURN SHOULD MATCH WITH REPORT'S DESIGN TIME FIELDS
}
}
}
----------------------------------------------------------

NOTE: If you are getting following error while accessing the WebPart page containing ReportViewer

Microsoft.SharePoint.Portal.Analytics.UI.ReportViewerMessages, Microsoft.SharePoint.Portal, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c does not implement IReportViewerMessages or could not be found

Try either of following to fix it

1In web.config of SharePoint, comment the following line under
1. <appsettings >
< ! -- < add key="ReportViewerMessages" value="Microsoft.SharePoint.Portal.Analytics...... / > -- >

or

2. Add following to < appsettings >
< remove key="ReportViewerMessages" >

------------------------------------------------------

LinkButton in SharePoint - Not firing Click Event

2009-12-22T00:41:00.003+11:00

I had a sitution to stream a file from SQL Server.
ASP.Net LinkButton was used in the ITemplate to use in GridView and Click event was defined with statements like

response.AddHeader("Content-Disposition", "attachment; filename=" + fileName );
response.AddHeader("Content-Length", blob.Length.ToString());
response.ContentType = "Application/x-msexcel";
response.BinaryWrite(blob);

Everything was working perfect in WebApplication. When the webpart was deployed to SharePoint, the server side click event fired only once. After that the link became irresponsive. If the page is refreshed, the link worked once again for 1st time.

After several googling, found that SharePoint stores time-stamp on client side for security reasons and avoids multiple post-backs for the same control.

There are 2 ways to over-come this issue. Just add an appropriate line as below

1. Generic way

imageButton.OnClientClick = "this.form.onsubmit = function() {return true;}";
or
hyperLink.OnClientClick = "this.form.onsubmit = function() {return true;}";
or
linkButton.OnClientClick = "document.getElementsByTagName(\'form\')[0].onsubmit = function() {return true;}";

2.Specific to SharePoint

linkButton.OnClientClick = "_spFormOnSubmitCalled = false;_spSuppressFormOnSubmitWrapper=true;";

After adding single line (one of the above), the webpart worked like a charm.

Composit Control Tips

2009-10-14T17:09:00.003+11:00

Came across this useful link about Composite Control.

http://skysigal.xact-solutions.com/Articles/tabid/434/ctl/ArticleView/mid/1024/articleId/36/Default.aspx

Read RSS and Atom feed in C#

2009-09-18T21:49:00.008+10:00

I had a requirement to read RSS/Atom feeds from blogs and store in SharePoint List.
I remember we had to go for separate framework to read the feeds and parse it. In that case we need to refer the framework in our project and install that assembly in Bin or GAC.

Now with .Net 3.5, life has become much easier.

Yes, with the namespace 'System.ServiceModel.Syndication' it is just few lines of code to read and parse the feeds either RSS or Atom.

Just add reference to 'System.ServiceModel.Web' to your project and include above namespace in your class, thats it.

Below is the code i used.
XmlReader reader = XmlReader.Create(curUrl);
SyndicationFeed feed = SyndicationFeed.Load(reader);
string title = String.Empty;
string link = String.Emplty;
DateTime dateTime = null;
foreach (var feeditem in feed.Items)
{
title = feeditem.Title.Text;
dateTime = feeditem.PublishDate.LocalDateTime;
link = feeditem.Links[feeditem.Links.Count -1].Uri.OriginalString;

//Do your tasks here
}

Easy to deploy and maintain too.
Happy Coding
வாழ்க வளமுடன் :)

Useful SharePoint Links

2009-09-18T21:41:00.003+10:00

Building CAML Query

2009-07-22T16:23:00.003+10:00

Found this useful site details about building CAML query.

http://sharepointmagazine.net/technical/development/writing-caml-queries-for-retrieving-list-items-from-a-sharepoint-list

Thanks Boske.

SharePoint Tools

2008-12-18T20:56:00.004+11:00

Ok friends, its very long since my last post. I will make sure that i update this blog regularly. To start with, here are the tools often used during SharePoint development.

1. SharePoint Tips Utility Pack - Developed by my ex-colleague Ishai.
This tool has many functions. Setting the properties of a field and managing Event Listeners were we largely used among them.
Mate, you are champion. I am really proud that I was your team member. You have answer for all SharePoint questions.

2. Stramit SharePoint 2007 Caml Viewer
This tool can be used to see the GUIDs of any lists and views very easily. Also all the fields and its internal names can be easily seen using this tool.

3. U2U CAML Query Builder
Last but not least, the most useful tool for building CAML queries to use in SharePoint object model coding.

"Trying to use SPWeb object that has been closed.." Error

2007-06-26T16:28:00.004+10:00

We were getting “Trying to use an SPWeb object that has been closed or disposed and is no longer valid.” in our MOSS -Workflow project.

After investigating all the source codes, I found the error causing statement in WebPart class.

The best practice is to dispose objects either by calling Dispose() in finally block or with using clause.

The snippet causing problem in our project was

SPGroup group;
using (SPWeb web = SPContext.Current.Web)
{
group = web.Groups[“Administrators”];
this.DisplayText = "Submit for Approval";
:
:
}

Here, the object is not really created in the memory, only the reference to the exisiting object is got and used. We should not dispose the current context web object manually in our code.

More information about best practice can be found at
http://msdn2.microsoft.com/en-us/library/ms778813.aspx

Happy Coding :)

Extending stsadm.exe with custom actions

2007-06-19T16:00:00.000+10:00

Stsadm.exe command can be extended by inheriting
Microsoft.SharePoint.StsAdmin.ISPStsadmCommand interface.

The actual process involves two steps.

Creating the configuration xml file.
Creating a class that implements ISPStsadmCommand interface.

Configuration file
The configuration xml file indicates to stsadm.exe which operations are available. This configuration file must follow well known naming convention stsadmcommands.<customcommands>.xml where <customcommands> can be any meaningful name but must be unique. Through this naming convention for configuration files, stsadm.exe implements a pluggable architecture for declaring custom operations.

<?xml version="1.0" encoding="utf-8"?>

<commands>

<command name="<name for command>" class="<namespace>,<class>,Version=<version>,

Culture=neutral,PublicKeyToken=<token>">

</command>

</commands>

The configuration file itself is a simple XML document with a root element containing one or more sub-elements. These sub-elements are where we declare custom operations and include two attributes name and class. The name attribute indicates the name of the operation to be executed by stsadm.exe. Note that the exact value of the name attribute will be specified by an administrator at runtime using the -o named parameter in order to execute the declared custom operation. The second attribute class specifies the class and .NET Assembly name where our classes that implement the ISPStsadmCommand interface.

.Net assembly
The .Net assembly containing the classes has to be placed in GAC. Each operation requires separate class inheriting ISPStsadmCommand interface. The ISPStsadmCommand interface has two methods to implement.
1. GetHelpMessage – this method returns help and usage information.
2. Run – this method actually does the custom operation.

class CustomActivateFeature : ISPStsadmCommand
{
//method to return help message
public string GetHelpMessage(string command)
{
//named parameters expected
return "-url ";
}

//method called to perform the action
public int Run(string command,
System.Collections.Specialized.StringDictionary keyValues,
out string output)
{

//assign value to variables
if (keyValues.ContainsKey("url"))
{
url = keyValues["url"];
if ((url == null) (url.Length == 0)) output += "url cannot be empty";
:
:

Deployment
The deployment process involves two steps.
1. Copy the configuration file (stsadmcommands.feature.xml) to [12 Hive]\CONFIG folder.
2. Copy the DLL file to GAC.

Now we can perform our custom actions using stsadm.exe by typing

stsadm.exe –o <name we have specified in xml file> <named
parameters> at command prompt.

It can be very useful to include in script/batch file for actions like backup, restore or some other automated actions.

Custom property of Webpart - dynamic DropDownList

2007-06-12T17:13:00.000+10:00

Custom properties can be included directly by including the properties (GET-SET accessor) in the web part class. Based on the return data type of the property, corresponding UI control will be rendered at run time.
Ex. If there is a property in webpart class as below

private string columnName = “”;

[WebBrowsable(true),
Personalizable(true),
Category("Web Part Settings"),
DisplayName("Site Column name."),
WebDisplayName("Site Column name."),
WebDescription("Site Column name.")]
public string ColumnName
{
get { return columnName; }
set { columnName = value; }
}

Note: WebBrowsable and Personalizable attributes should be true.
Above property will be rendered as text box on the property pane.

To display dropdown list if values are static, create a enum containing all static values and use that enum in the get-set method.
Ex:

public enum searchscope
{
All_Sites,
Current_Site
}

private searchscope searchScope = searchscope.All_Sites;
[WebBrowsable(true),
Personalizable(true),
Category("Web Part Settings"),
DisplayName("Search scope."),
WebDisplayName("Search scope."),
WebDescription("Detirmines the scope to search.")]

public searchscope SearchScope
{
get { return searchScope; }
set
{
searchScope = value;
}
}

The above code will diplay a dropdown list with two static values.

Ok, what we have to do if the values are to be dynamically read from sharepoint list or some other source.
1. Create a class that inherit from Microsoft.SharePoint.WebPartPages.ToolPart
2. Create and initialise DropDownList
3. Add the drop down list to the Controls in the overridden method CreateChildControls.
4. Override ApplyChanges() method to update the value in the main webpart class.

class CustomToolPart : ToolPart
{
DropDownList ddlTypes = new DropDownList();
:
:

public CustomToolPart()//Constructor
{
this.Title = "Select Type";//Set the title for our custom tool part.
}
protected override void CreateChildControls()
{
PopulatePageTypes(); //Method to populate the drop down list.
Controls.Add(ddlTypes);
}
public override void ApplyChanges()
{
//Logic to update the variable value in main webpart class
}
}

Now in the main web part class,
1. Override GetToolParts() method
2. Create and initialise our custom class.
3. Add to ToolParts array.

public override ToolPart[] GetToolParts()
{
ToolPart[] toolparts = new ToolPart[3];
WebPartToolPart wptp = new WebPartToolPart(); //WebPart's default properties
CustomPropertyToolPart cptp = new CustomPropertyToolPart(); //Standard Custom properties added to webpart like ColumnName and SearchScope.
CustomToolPart ctp = new CustomToolPart(); // Our custom property ToolPart

toolparts[0] = wptp;
toolparts[1] = cptp;
toolparts[2] = ctp;

return toolparts;
}

That’s all. Deploy the webpart and you can see the dropdown list with dynamic values when you modify the properties of the webpart.

Steps to setup AJAX on Sharepoint Server 2007

2007-05-21T21:26:00.000+10:00

1. Download ASP.NET 2.0 AJAX Extensions 1.0 from http://ajax.asp.net/default.aspx
2. Install ASP.NET 2.0 AJAX Extensions 1.0 on the server.
3. Update web.config file of the server as directed in http://ajax.asp.net/docs/ConfiguringASPNETAJAX.aspx
4. Script manager has to be added to enable AJAX on webpage,

It can be added in master(template) page to enable the whole website to be AJAX enabled
The class AjaxBasePart.cs found in http://www.capdes.com/2007/02/microsoft_office_sharepoint_se.html can be used as base class of our class.
Adding Script Manager to our class.

Thats it. Now you can create your own AJAX enabled solutions.

Videos for introduction and implementation of AJAX can be found at http://www.asp.net/learn/videos/default.aspx

There are a lot of AJAX enabled controls (ASP.NET AJAX Control Toolkit) available at http://ajax.asp.net/downloads/default.aspx which can be used directly on our website as like as custom user control.

Have fun.